Spectral index maps before and after applying a shift to the 1.3 mm image to correct for systematic gradients observed in the fields of Corona Australis and IRAS 16293 A/B (Ophiuchus). The left and right images correspond to before and after the correction, respectively. The upper-right corner contains the minimum and maximum values of the spectral index in the map, considering only the pixels with errors up to 0.2.